Before we discuss the evolution of Islamic state throughout the history, let us first see how political leadership was formed and passed during the early era of Islam. When the Prophet Muhammad SAW was still alive, he had two authority within his hands, i.e. religion and politic. However, neither the Koran nor the Prophet ever stipulate any specific form of state to begin with. In any case, it was an informal form of leadership.
When the Prophet died, a huge debate occurred between his devoted followers ("Sahabat") on who will replace the Prophet's position as the leader of the people of Makkah and Madinah. If there is actually a clear concept of leadership and state in Islam, surely such debate would never happen, but as further recorded in various history books, the debate was so fierce that the Prophet's burial process was delayed for around 3 days. Without a doubt, this was the first political crisis in the moslem history. Many issues were discussed in that debate as people were trying to find the most suitable candidate, including ethnicity, seniority, and also capability of the candidates. You may wish to consider the fact that at that time, tribal issues were quite dominant, and there was a huge risk that our young Islamic community would be shattered due to this leadership succession. Miraculously, the community survived its first political trial.
When the debate was finally over, the Sahabats who attended the meeting agreed that the first person who converted into Islam, Abu Bakar, should become their first leader, the first caliph of the Islamic society. They also agreed that only political leadership which shall be passed to Abu Bakar, while religious leadership was deemed over with the death of the Prophet. After all, no one would be able to receive directly the wisdom of God other than the Prophet. Abu Bakar led the Islamic community for about 2.5 years. After he died, Umar bin Khatab became the next caliph through a direct appointment from Abu Bakar. Some prominent moslem historians claim that Abu Bakar has discussed Umar's appointment with other respectable Sahabats, and all of them agreed with his appointment. Nevertheless, it was Abu Bakar who directly appointed Umar as his successor. So by now, we could see 2 types of leadership succession. Later on, Ustman bin Affan became the successor of Umar. How did it go?
Umar appointed 6 members from the Sahabats (the "Council") with the task to elect the next caliph from the Council's own members. Again, another form of leadership succession. In my opinion, Umar was a great leader and he clearly understood that without any clear guidance, Abu Bakar's decision to directly appoint him would be considered as a binding precedent by the Islamic community if he also did the same in appointing his successor. Since he actually opposed the direct appointment mechanism, he decided to create a new mechanism for leadership succession. Then came Ali bin Abu Thalib as the 4th caliph.
After the death of Ustman due to a coup, Ali was elected as the new caliph through a direct election by the whole people of Madinah, and therefore became the first and also the last caliph who was appointed through a public election. The elections of Ali is a strong evidence that the early Islamic community practiced democracy, though maybe not as complex as today. Despite the inconsistencies in leadership succession mechanism, there is a general rule that we can learn from the above story. All of the 4 caliphs were considered as capable and respected leaders, and none of them were appointed because of family relationship with the previous ones. For such a young community with deep tribal issues, this was a great achievement indeed.
Unfortunately, this great system ended when Muawiyah bin Abu Sufyan gained the title of caliph. I'll reserve the story on how he got that title for another post (maybe when we discuss the Shia political movement), though I can say it here that it is a controversial one, and many historians are still disputing whether Muawiyah had valid grounds to obtain that title from Ali bin Abu Thalib. How did Muawiyah end the caliphate system of leadership succession? He appointed his own son, Yazid, as his successor, and by such act, he turned the caliphate into an ordinary kingdom. Yes, the Islamic people are still calling their leaders as caliphs, but they are not different from kings who gained their title simply because of family relationship.
The Evolution of Islamic State: Experience or Religious Doctrine?
Based on the above story, we can safely conclude that in terms of political leadership succession, the early Islamic community did not have a single established system. Furthermore, the mechanics existing at that time were not simply derived from Godly sources, rather they were created from trials and errors, the experiences of the caliphs and the moslem community as a whole. This is how the concept of Islamic state evolves within more than 1,400 years, experiences rule.
Under Abu Bakar's leadership, the Islamic community was still very small, and Abu Bakar spent most of his time fighting insurgents, mostly lead by fake prophets who tried to gain control over the moslem community. Thus, you won't find complex state organs under his era as his government mostly resembled tribal leadership. The only thing that may be considered as an evidence of modern state is the existence of baitul-mal, or the state's treasury, though at that time it mostly dealt with war's booty. Nevertheless, it is still a unique concept, as the war's booty is considered as people's assets and managed by the "state" through the baitul-mal It was actually under Umar bin Khatab leadership when Islamic community started to grow into a more formal state. During Umar's period, the Islamic community expanded their power aggressively and they succeeded in controlling many new areas. As more and more areas fell under the control of the moslem community, Umar realized that he was no longer able to directly supervise those areas. As a direct consequence, there is a necessity to appoint representatives of the caliph to lead and supervise those new areas, and suddenly, we have governors position.
Soon enough, official judges position were also available as the new community need professional lawyers to settle their disputes and uphold the law. In short, Umar fully understood his role as a caliph, administering the government, managing the needs of the people, and establishing a good foundation for a powerful state. He also believed that the caliph position is a political and administrative position. In other words, there's nothing holy about it.
Sadly, as the caliphate turned into a kingdom, the nature of the caliph's position was also changed. In order to secure the caliphs' power, new doctrines were formulated, they were seen as the representatives of God, their authorities over the people were granted by God. Some prominent scholars rejected this notion, and claimed that this is not the ideal form of Islamic leadership. I share the same view, but then again, it is a logic decision from the caliphs. When you are no longer elected by the people, you absolutely need a good doctrine to support your power, and what would be better than using God's name? These caliphs were not stupid, some of them were also good lawyers and soon they established caliphate's official scholars with the task to formalize the doctrine, changing the status of the caliphate from a mere administrative body of government into a holy state. It should be noted that in those eras, many scholars did not want to cooperate with the caliphs. Those who were willing to cooperate with the caliphate will not be respected as they will be considered as people who sold their soul to the devil.
The Illusion and Its Grave Consequences
For the sake of fairness, I won't say that the concept of Islamic kingdom is entirely bad, in fact the caliphate had their good moments in the history of mankind. But the damage has been done, this whole business creates an illusion to the Moslem community that the Islamic state, the caliphate, is a product of God, part of the religion, instead of a product derived from political experiences. There are some grave consequences when the caliphate is deemed as a part of religious doctrine, and we can easily spot one, i.e. the fact that most people who wish to establish an Islamic state focus most of their time in defining the characteristics of the Islamic state instead of how the state can be useful for its people.
In Umar's era, he did not bother the formal structure of the state, what bothered him the most was his people's prosperity. Another major problem is that this illusion also creates a false hope to many people. From historical perspective, the existence of the Islamic state does not automatically solve all problems. The history is very clear on this subject and it would be a huge lie if Abu Bakar, Umar, Ustman and Ali did not face critical and complex problems during their respective leadership. In some cases, they were successful, in other cases, they faced failures. However, some people buy the lies and completely believe that the establishment of the caliphate will solve all problems. I can only hope that this people could face the cruel reality someday.
Conclusion
We have reached an understanding that the concept of Islamic state is mostly derived from experience not religious doctrine. As a consequence, there is no use for discussing the formal structure of the Islamic state. Don't waste our time preaching the greatness of the Islamic state and the promise that it will bring, instead, we should really focus on how we can manage the state to provide better service to the people, and I am certain that this is relevant for the current Indonesia. Hope it's useful :) Happy Independence Day my beloved Indonesia!